The present exemplary embodiment relates to a sliding door assembly. It finds particular application in conjunction with a sliding passenger door for a vehicle, and will be described with particular reference thereto. However, it is to be appreciated that the present exemplary embodiment is also amenable to other like applications.
In conventional vehicles having a sliding door, the door is typically mounted on several slide rails. Typically, upper and lower slide rails are situated, respectively, above and below an opening in a body panel of the vehicle which the door is adapted to provide selective access. A third slide rail, or middle rail, is commonly provided at a vertical position between the upper and lower slide rails, and extends rearwardly from the opening in the body panel of the vehicle. Roller carriages engaged with the slide rails support the door for sliding movement between a closed position and an open position.
During operation of the door, the roller carriages follow the slide rails and thereby guide the door initially outwardly from the side of the vehicle. Once the door is spaced outwardly from the vehicle body, it can then slide parallel to and spaced apart from the body panel as it is advanced rearwardly to its open position. In the open position, the carriage associated with the middle rail supports the weight of the rear portion of the door, while the carriages associated with the upper and lower slide rails support weight of the front portion of the door.
In the past, efforts have been made to reduce the visibility of the middle rail, as some consumers find its presence detracts from the overall appearance of a vehicle. Early attempts at concealing the middle rail included locating the middle rail just below a rear window of the vehicle so that it blends with the window lines. Other approaches have employed covers to conceal the middle slide rail, but still a small gap must remain between the cover and the body for a support arm to connect the door to the roller carriage.
While these attempts to lessen the visual impact of the middle slide rail have been, to some extent, successful in decreasing the size of the middle rail opening, the middle rail opening still remains and, as such still detracts from the vehicle's appearance.